Perpetual calendar



April 27,1937.

Filed Jan. 16, 1936 J. K. Z. LAMPE PERPETUAL CALENDAR mm K wpmhm La 4 Sheets-Sheet 1 DAY DAY OF THE MONTH CENTLJRV NEW STYLE INVENTOR. "1pc ATTORNEYS April 1937- J. K. 2. LAMPE 2,078,450

PERPETUAL CALENDAR Filed Jan. 16, 1936 4 Sh eetSSheel'. 2

INVENTOR. JBhan K rt] zzpp fdulampz BY WO QQALEN TTO EYS April 27, 1937.

.1. K. 2. LAM PE PERPETUAL CALENDAR Filed 'Jan. 16, 1936 4 Sheets-Sheet 4 W413HQL001405665740O32 Aw /w CW 5 14040404046 3e3 que3 3 3 3 34343 2 2 2424242323232322 13131 121 12 1E4I 1 1 1i I INVENTOR. Iflmn Karel ZapP/lhldf LqmPC ATTORNEY. I

Patented Apr. 27, 1937 FATENT OFFICE PERPETUAL CALENDAR Johan Karel Zeppenfeldt Lampe, Oranjestad, Aruba, Dutch West Indies Application January 16, 1936, Serial No. 59,381

7 Claims.

This invention relates to improvements in calendars by means of which the day on which any date falls may be determined 'either under the old style or the new style calendar. 5 The main object of the invention is to provide in mechanical form a mechanism by means of which the day name of any particular date from 45 B. C. until about 21,000 A. D. may be determined by simple manipulation of the mechanism.

This invention resides substantially in the combination, arrangement, construction and relative location of parts, all as will be set forth in detail below in connection with the attached drawings.

The many objects of the invention will be more apparent from the detailed description of one embodiment of the invention.

In the drawings,

Figure 1 is an end elevational view of a mechanism in accordance with this invention;

Figure 2 is a side or face elevational view of the new style side of the mechanism;

Figure 3 is a cross-sectional view taken on the line 33 of Figure 2;

Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 1;

Figures 5 to 16, inclusive, are views showing the various scales or tables employed on the various drums or cylinders of the mechanism.

The device as illustrated comprises a base plate 30 I having a felt or other protective covering 2 secured to the bottom face thereof. At 3 aud t are the end plates of the casing which together with the face covering 5 when mounted on the base I provides a completely closed casing for the various parts of the mechanism. A reinforcing plate 6, which fits snugly within the casing at the base, serves to aid in mounting it thereon. The details of construction of the casing and mounting may, of course, be varied by those skilled in the art without departure from the invention. The form illustrated represents but one embodiment thereof and I do not desire to be limited to the particular form illustrated.

The face covering 5 may, as are the other parts, be made of suitable metal having a finish suitable for the purpose. Mounted Within the casing for rotation by means of knobs externally thereof are a series of cylinders or drums upon which the various scales or tables are mounted. In to the top of the casing is mounted a cylinder, which may be termed the day cylinder, and is shown comprising the outer cylindrical portion l closed at the ends by means of discs 0 and El which Lil fit within the ends of the cylinder and are secured 55 thereto in any suitable manner, such as by soldering. This cylinder is rotatably mounted in the casing by means of a pair of shafts l0 and H which are rotatably journalled in the sleeves l3 secured to the casing as shown. The ends of the shafts are provided with knobs l4 and M5 by means of which the cylinder may be rotated. The shaft [0 is provided with a small collar l2 which rests against the inner end of the left hand bearing sleeve l3 (Figure 4). Thus the sleeves, knobs and collar cooperate to hold the cylinder axially aligned with the opening 49 on the new style face (see Figure 2). There is a corresponding opening on the old style or opposite face properly positioned as will be explained later. Mounted upon the shaft I l as shown is a metal disc I] which has thirty-six notches or teeth formed on the periphery thereof, as is clear from Figure 3. This disc is secured to the shaft H for rotation therewith. At i8 is a flat spring which is secured in the casing by means of a tab I9 and is provided with a bent end positioned to engage the notches of the disc ll. By this mechanism the rotation of the cylinder may be divided into thirty-six steps.

At 20 and 2! are a pair of cylinders, which together may be termed the date cylinder. The cylinder 20 is closed at both ends by means of discs while the cylinder 2i is only closed at one end by means of a disc so that it may telescope with the cylinder 20. all of the cylinders like cylinder 1 consist of a metal tubular portion closed by means of end discs secured therein. The right hand disc of cylinder 23 and the disc of cylinder 2| are provided with a square central opening so as to receive the square portion of shaft 38. The left hand disc of cylinder 20 is provided with a threaded central opening to engage the threaded portion of shaft 35. The shafts 35 and 3B are journalled in sleeves l3 mounted on the casing as before and are provided with operating knobs 2'! and 3|, respectively. The shaft 35 is provided with a positioning collar 35a. The shaft 38 is provided with a metal disc M which has ten teeth or notches on the periphery thereof which are engaged by means of a flat spring 52 mounted on the casing. With this arrangement these cylinders may be independently rotated. When knob 3| is rotated, cylinders 20 and 2t rotate together, but when knob 2'! is rotated cylinder 20 moves axially only sliding along the square portion of shaft 38.

The cylinder 22, which may be termed the month cylinder, is mounted for rotation inv the casing by means of a pair of shafts Illa and Ila which are journalled in sleeve H as before. Shaft It may be here noted that d ltla is provided with a collar lQa and shaft Ha with a notched metal disc 33, the periphery of which is divided into twelve equal parts. A spring is mounted on the casing engages the notches of this disc. The shafts liia and Ha are provided with operating knobs 28 and 32.

Cylinders 23 and 2 1, which together may be termed the century cylinder, are like cylinders 2t and 2i and are similarly constructed. Cylin der 24 is slidably mounted on the square portion of shaft 39 which is journalled in the sleeve [3 and provided with an operating knob 33. Cylinder 23 engages the threaded portion of shaft 36 whi h is journalled in the sleeve i3 provided with a knob 29 and a collar 33. A metal disc 45 having ten notches on the periphery thereof is secured to the shaft 33 and is engaged by a flat spring 45 mounted on the casing. Here again the rotation of knob 33 causes both cylinders 23 and 24 to revolve, while the rotation of knob 29 causes cylinder 23 to move axially.

Cylinders 25 and 26, which together may be termed the year cylinder, are similar to the above and are respectively mounted on the threaded portion of shaft 3'! and the square portion of shaft 40. These shafts are journalled in the sleeves 83 mounted on the casing and are provided with the operating knobs 30 and 3 5, respectively. A collar 38" is secured to shaft 31 and a metal disc l? having its periphery divided into eleven notches is secured to the shaft 4t and engaged by means of a spring 48 mounted on the casing. These cylinders may be operated rota tively together and cylinder 25 may be moved axially without rotation of cylinder 26.

The faces of the casing are provided with windows positioned with respect to the date, month, century, and year cylinders, as will be apparent from Figure 2. The date window is indicated at 50, the month window at 51 the century window at 52, and the year window at 53. A similar set of windows in alignment with these is provided on the other or old style face of the casing.

As is clear from Figure 3, there are four other cylinders mounted in the casing behind those shown in Figure l. The cylinders behind those in Figure 4 are reversed end to end in the actual machine with respect to those shown in Figure 4 and should therefore be partially visible in this figure. They have been omitted from Figure 4, however, for sake of clarity. It will be apparent upon consideration that end for end reversal as between the front and rear set of cylinders is desirable so that each set of cylinders will be operable from the same side and same direction of rotation of the knobs for both the new style and the old style uses. This simplifies the use of the device. However, since this arrangement is not necessary but a preferred convenience, Figure 3 shows the notched discs for both sets of cylinders on the same side of the machine. This has been done for the purpose of simplifying the drawings, although, as noted above, the right hand set of cylinders of Figure 3 would be reversed end for end and the right hand set of notched discs Ma, dim, ita. and lia; would be on the far side of the machine and not appear in this figure. However, the arrangement of Figure 3 would be entirely operative but would require a reverse manipulation of the knobs and cylinders, which is not desirable simply because it would be confusing to the ordinary user. Of course, it is obvious that for such reverse manipulation of the knobs and cylinders the numbers on the charts for these cylinders would be reversed to give them the correct sequence and position for reverse manipulation.

The construction and mounting of these cylinders are the same as the corresponding ones described with the exception that the disc 4711 on the teeth of the year cylinders is divided at its periphery into ten equal parts instead of eleven as previously described. As viewed in Figure 3,

a disc 43a having twelve notches on the periphi.

cry thereof and engaged by a spring 4461;. This is the month cylinder, old style. Mounted on shaft 39a is a cylinder 24a corresponding to cylinder 24 and nesting with a cylinder corresponding to cylinder 23 but not appearing in Figure 3.

The shaft 39a. is provided with a disc 45a having ten notches on the periphery thereof and engaged by the spring 46a. These cylinders provide the century cylinder, old style. Mounted on the shaft 40a is a cylinder 26a corresponding to 3 cylinder 26 and nesting with a cylinder corresponding to cylinder 25 but not appearing in Figure 3. Secured to the shaft ilm is a notched disc 41a having ten notches in the periphery thereof and engaged by the spring 48a. cylinders provide the year cylinder, old style.

In order to clarify this portion of the description it will be noted that cylinder i is used for both the old style and the new style. The four cylinders to the left in Figure 3 are used for the new style and the cylinders to the right are used for the old style.

A description of the scales or tables which are applied to the various drums will now be given in detail. No reference will be made to the theory and calculations by means of which these tables were derived. The tables as presented in the drawings are complete and accurate and when incorporated in the machine are sufficient to determine the day on which any particular date falls from 45 B. C. to 21,006 A. D. The table of Figure 5 is printed or otherwise impressed on a sheet 58 of any suitable material, such as paper, which has a width equal to the axial length of cylinder l and a length equal to the circumference of that cylinder so that when applied thereto the end edges abut and form a mantle around the cylinder. The table is of the form shown in Figure 5 and has thereon two number lists 58b extending along opposite sides thereof and increasing from opposite ends. These lists each comprise the numbers 0 to 35, inclusive. Between these rows of numbers are two rows 58:: reading in reverse direction from opposite ends of the sheet of the days of the week. These lists egin with Saturday and run through Friday, after which they are repeated, as is clear from Figure 5. This sheet is attached to the cylinder 'i in any suitable manner but must be circunr ferentially placed thereon so that a horizontal plane through the of the cylinder will bisect one of the horizontal rows of the sheet. At this time, of course, cylinder l should be so positioned that the spring it is in one of the notches. Under these conditions, one of the day names and its These corresponding number in one of the lists will appear in the window 49 and one of the day names and its corresponding number in the other list will appear in the corresponding window on the other side of the casing. By placing the sheet on the drum in the manner described the day names and numbers will appear centered in the windows.

The scales or tables for the date cylinders 28 10 and 2! are shown in Figures 6 and 7, respectively.

The length of the sheet 65) is equal to the circumference of cylinder 20 and its width is equal to its axial length. There appears on this sheet a series of numbers Bila representing the day 15 date and under them a series of smaller numbers 632), which are termed the date ciphers. This sheet is applied to cylinder 20 when positioned with the spring 42 in one of the notches so that the vertical distance occupied by a date number 20 and a date cipher is bisected by a horizontal plane through the axis of this cylinder. In a similar way the strip BI is applied to cylinder 2! at the left hand edge thereof. This strip is just long enough to fit around the drum 2i and is of 25 sufficient width to receive the numbers thereon, comprising the day numbers 65a and the date ciphers filb. By means of these two tables the day date for any day of the month may be made to appear in window 50. The day numbers in table 30 60 represent the tens and the day numbers in the table 6| represent the units. It will be seen then that by rotating cylinder 2i with knob 3i any number from to 9 may be made to appear in the right hand half of window 59. Likewise, by

. rotating shaft 35 by means of knob 2'! any day date in a horizontal row in table 60, together with its date cipher, may be made to appear in the left hand half of window 50.

It will be noted, as stated before, that when cylinder 2! is revolved cylinder 20 turns with it. This emphasizes an important feature in applying the tables 60 and 6! to these cylinders. They must be applied so that the large numbers in the first row at the top of table 69 are in alignment 45 with the large numbers at the top of table i. In

other words, the numbers in the two tables are aligned in an axial direction, which relative position they always maintain because cylinders 20 and 2! engaging the square portion of shaft 38 54) cannot turn relatively to each other. It will be seen then that by properly manipulating knobs 21 and 3| any number from 1 to 31 may be set up in window 50. At this point it may be noted that the vertical columns of these tables have ten large numbers, which explains the reason for providing disc 4| with ten notches. The corresponding cylinders for the old style side of the calendar are provided with exactly the same tables,

as shown in Figures 6 and 7.

(3-1: The table in Figure 8 is .applied to the month cylinder 22. As before, it comprises a sheet 59 of suitable material of a width equal to the axial length of cylinder 22 and a length equal to the circumference thereof. As shown in Figure 8,

.3 this table consists of a list of the month names 590. with a series of small numbers under each. The numbers 5% under the left hand end of each month name are the common year ciphers, while the numbers 590 under the right hand end of o each month name are the leap year ciphers. All of the leap year ciphers should appear on the table in a different color from the common year ciphers. For example, the common year ciphers may be printed in black ink and the leap year 75 ciphers in red ink. This table is applied to cylall inder 22' so as to fit around the circumference thereof and should be applied so that a horizontal plane bisecting the axis of this cylinder will bisect the vertical distance containing any month name and its common and leap year ciphers when spring 44 lies in one of the notches. The corresponding cylinder for the old style calendar, which is shown at22a. in Figure 3, is supplied with a table exactly like that just described and shown in Figure 8. The month names and their cipher numbers of cylinder 22 appear in window 5| on the new style side of the calendar, while the same indications for the cylinder 22a will appear in the corresponding window on the old style side of the calendar.

The tables illustrated in Figures 9 and 10 are applied to the century cylinders 23 and 24 and are properly dimensioned to fit thereon. The sheet of paper or the like t2 has thereon the century table comprising a series of large numbers 62a representing the centuries by tens. The small numbers thereunder are the century ciphers, as indicated at 621). On the sheet or strip 63 the large numbers 63a represent the centuries by units and the small numbers 63b thereunder represent the corresponding century ciphers. These sheets are applied to these cylinders in the manner described in connection with the cylinders 20 and 2| so that the numbers of the first row of sheet 62 will align with the number of the first row of sheet, 63 and the vertical distance occupied by any century number and its century cipher will be bisected by a horizontal plane through the axes of the cylinders when the spring 46 lies in one of the notches. These numbers and horizontal rows on the two tables will then always remain in axial alignment because of the square portion of shaft 39. By rotating knob 33 any number on table 63 may be brought in the right hand portion of window 52 and any number in the same row in table 62 may be brought into the left hand portion of this window by rotating knob 29. It may be here noted in view of the fact that different colors were first met with in describing Figure 8 that all of. the printing on sheets 58, 6! 5!, 82 and 63 are printed in one color, preferably black.

The tables that are used on the corresponding or century cylinder for the old style side of the calendar are shown in Figures and 16. The number of years before Christ by tens are shown by the large numbers 68a on the sheet 68 while the small numbers thereunder, shown at 681),

, represent what may be termed the spliced year This same sheet has thereon a double i ciphers. column separated from the other members by the heavy line 680, a series of large numbers 68d, with small spliced century ciphers Eifie there under. This table is applied on the old style side of the calendar to the cylinder corresponding to cylinder 23. The table of Figure 16 is applied to cylinder 24a, Figure 3, corresponding to cylinder 24. This table comp-rises a long narrow sheet 69 having thereon the large numbers representing the century units, as indicated at 69a, and thereunder the small spliced century ciphers 6%. All the numbers on these two charts are printed in the same color, preferably black. These tables are applied to the cylinders so that the top row of numbers of each will be in axial alignment and the vertical space occupied by them will be bisected by a horizontal plane through the axes of the cylinders when the spring which controls the cylinder is in a notch. It may be here noted that the table to the left I red, and the rest are in black.

' as indicated in Figure 13.

of line 68c and the table 69 provide the year numbers for years before Christ, and the numbers of table 53 to the right of line 68c and the numbers of table 69 cooperate to provide the century numbers A. D., old style.

The tables of Figures 11 and 12 represent the tables for the year cylinders 25 and 26, new style. The sheets 54 and 55, on which these tables are printed, lit the cylinders as previously described. The large numbers 60a and $42) on the sheet 55 and the large numbers 65a and 65b on the sheet 65 represent the year numbers and appear in different colors. Those shown in solid black should be printed on the charts in black, while those shown in outline should be printed in a different color, preferably red. Under these year numbers are the small numbers 640 and which represent the year ciphers. The year ciphers on the two tables are likewise printed in different colors but this cannot be readily indicated in Figures 11 and 12. For this reason applicant will list them. In table 6 5, in the first horizontal row or" small numbers, reading from left to right, the numbers 3, 0, 4, and 1 are in In the second horizontal row, all the small numbers are in black. In the third horizontal row, the num bars 5, 2, 6, 3, and are in red, and the rest are in black. In the fourth horizontal row, the small numbers all are in black. In the fifth horizontal row, the small numbers 0, 4, 1, 5, and 2 are in,red,-and all the rest are in black. In the sixth horizontal row, all the small numbers are in black. In the seventh horizontal row, always reading from the left, the small numbers 5, 2, 6, 3, and

0 are in red, and all the rest are in black. In the eighth horizontal row, all the small numbers are in black. In the ninth horizontal row, the small numbers 0, 4, 1, 5, and 2 are in red, and all the rest are in black. In the tenth horizontal row, all the small numbers are in black. In the eleventh and last row, the single small number is in red.

In the table 25 of Figure 12, reading downwardly, the small numbers 3, 5, 1, 3, and 0 are in red, and all the other small numbers are in black. These represent the new style charts for cylinders 25 and 25 and are applied thereto so that the first horizontal row of each is axially aligned and the vertical distance occupied-by this row, including large and small numbers, is bisected by a horizontal plane through the axes of the cylinders when spring '38 lies in one of the notches. These numbers appear in the window 53.

The charts of the corresponding old style cylinders are shown in part in Figures 13 and 14. They are exactly like the charts of Figtues 11 and 12 with these exceptions. There are only ten horizontal rows, with the result that the eleventh row of Figures 11 and 12 comprising large and small zeros are not used. The first number 65a in the first horizontal row on chart E6 and its year cipher are changed from black to red, Its first large number fi'l'o on chart fil remains red while its small number 57a is changed from a black 1 to a red 0. These charts are applied to the old style cylinders using the same precautions described above in applying the charts of Figures 11 and 12 to the new style cylinders.

The above description represents the entire structure comprising this invention. As previously stated, the calculations and theory em ployed in deriving the tables have not been given since they are not necessary to an understanding of this invention. In other words, if the disclosure as given is followed the device may be reproduced. It may be noted, for example, that the diameter of the various cylinders is immaterial just so long as the notched plates are provided with the number of notches disclosed herein. Likewise, for any particular size of cylinders the charts will be changed in proportion to fit thereon as described and the size of the numbers will be varied so as to occur in equal sized, equal distant rows around the cylinders.

The method of using the device both for old and new style will now be given.

In order to find the corresponding day of the week for any date, knob BI and knob 21 are turned until the number of that date appears in window 50. As previously noted, the units are brought into the window by turning knob 3! and the tens by turning knob 21. If the date number consists only of a unit this is brought into the window by turning knob 3 l, and knob 21 is turned until a blank space appears in the window in place of the tens number. The month cylinder knobs 28 and 32 are then turned until the name of the month appears in window 5!. Knob 33 is then turned until the units number of the century appears in the window and then knob 29 is turned until the tens number appears in the window. Finally, knob 34 of the year cylinder is turned until the unit number of the year appears at the right hand side and then knob 30 is turned until the tens number appears at the left hand side of window 53. The various ciphers, that is, the small numbers which appear in the difierent windows, are then added together. If, in the particular problem selected, the year is a common year, the black cipher at the left hand of window Si is included in the addition, while if the year selected is a leap year the red number at the right hand end of window 5| is included in the addition. When the sum is thus obtained the knobs l 4 and I6 are turned until this sum appears in the window, which will. be one of the numbers of the column 582) (Figure 5). The day for the date of the problem will be the name of the day appearing in the window opposite that number. When the numbers representing the number of years in the year window 53 are red,

this indicates a leap year, requiring that the 42, 62, 82, 14, 34, etc. will appear in two colors,

the tens in black and the units in red, then the common year cipher in black in window 5| is included in the addition.

When using the old style side of the device, the numbers indicating any year must be represented by four ciphers so that when a year has no number of centuries 00 most be taken as such. Thus the years 1, 2, 3, 4, 5, etc., must be set up as 0001, 0002, 0003, 0004, 0005, etc. The years before Christ must be taken on the old style century cylinder as 01, 02, 03, 04, 05, etc., representing, respectively, the years 1, 2, 3, 4, 5, etc.

When a leap century, such as 2000, 2400, 2800, 3200, etc., is set up on the year and century cylinders, two red ciphers will appear in the window 53 indicating the fact that a leap century set up is a leap century. However, if the ciphers that Since the century. table of Figure 9 does not show century numbers higher than 11 the following procedure is followed when the century numbers are higher than 11. For the number of centuries I I8, 8 is set up on the units table, Figure 10, in window 52, and 11 is set up on the tens table, Figure 9, in window 52. The century cipher is 0+0=0 as the ciphers 0 and 0 appear in window 52 under the tens-11-and the units-8.

When the number representing the tens is 1'2 use the tens number 8 of table, Figure 9, instead of 12, and diminish the result by 1. For 13 use 9 and diminish the result by 1. For 14 use 10 and diminish the result by 1. For use 11 and di- 15 minish the result by 1. For 16 use 8 and diminish the result by 2. For 17 take 9 and diminish the result by 2. For 18 take ten and diminish the result by 2. For 19 take 11 and diminish the result by 2. For 20 take 8 and diminish the result 20 by 3. For 21 take 9 and reduce the result by 3.

As noted above in connection with Figures 15 and 16, the tens for the years before Christ are set up from the table I5 by using the numbers to the left of line 580.

As a more specific operation of the machine, it will be assumed that we wish to find the day on which February 16, 1935, fell. To accomplish this, the month cylinder is rotated until February appears in the window 5 I. The date cylinders are 39 then revolved until the number 16 appears in the window 50. The century cylinders are rotated until the number 19 appears in window 52 and the year cylinders are rotated until the number appears in the window 53. The small numbers in window 56 are 3 and 6, the small number in window 5i is 3 (the left hand number 1935, not being a leap year), the small numbers 0 and 0 appearin-ginthe window 52, and the small numbers 2 and 0 appearing in the window 53.

These added up give the sum of 14. The day cylinder is then rotated until the number 14 appears in the window 49, in which also appears the Word Saturday, indicating that February 16, 1935, fell on Saturday. This data is shown set up in the Windows in Figure 2.

From the above description it will be apparent that this invention resides in certain principles of construction which may be embodied in other physical forms without departure from the scope thereof. I do not, therefore, desire to be strictly limited to the single example given by way of illustration but rather to the scope of the appended claims.

What I desire to secure by Letters Patent is:

1. A machine of the type described comprising a casing having five display windows therein, drums mounted in said casing opposite the respective windows, tables mounted on said drums containing numbers and day and month names 60 to be displayed in the windows, means for indexing the drums, means for effecting rotation thereof, said machine including five windows on the opposite side thereof, one of said drums being common to one window on each side of the casing, and four additional drums journalled in the casing opposite the other four windows, whereby the day name of any date, either new style or old style, may be found from 45 B. C. to 21,000

2. A machine of the type described comprising a casing having five display windows therein, drums mounted in said casing opposite the respective windows, tables mounted on said drums containing numbers and day and month names 76 to be displayed in the windows, means for indexing the drums, means for effecting rotation thereof, said machine including five windows on the opposite side thereof through one of which the data of one of said drums is displayed, four additional drums journalled in the casing opposite the other four Windows, indexing means for positioning said additional drums, and means for rotating the drums, whereby the day name of any date, either new style or old style may be found from 45 B. C. to 21,000 A. D.

3. A machine of the type described, comprisin a casing having five windows therein, two drums, joui'nalled in the casing opposite two of the windows respectively, three two part drums journalled in the casing opposite the remaining three windows respectively, means for effecting independent rotation of all of the drums, the two parts oi the two part drums rotating as a unit, means for effecting axial movement of one part of each of the two part drums independently of the other unit, means for indexing the drums when they are rotated to position them, and tables mounted on said drums, the table on one of the two first mentioned drums consisting of the numbers 0 to 35 and the days of the week in chronological order and repeated so that the name of one day appears opposite each number, the table on the other of the first two mentioned drums consisting of the days of the month in chronological order and having two numbers undereach,tables on one of the two part drums representing the days of the months by tens and units and having small numbers thereundentables on the second of the two part drums representing the centuries by tens and units and having small numbers thereunder, and tables on the third two part drum representing the years in tens and units and having small numbers thereunder.

4. A machine of the type described, comprising a casing having five windows therein, a drum journalled in the casing opposite one of the windows having a table thereon consisting of a column of numbers from 0 to 35 and a column of day names in chronological order and repeated with a day name opposite each number, another drum journalled in the casing opposite another window having a table thereon comprising a list of the months in chronological order and each having two small numbers thereunder, a two part drum journalled in the casing opposite another of the windows, means for rotating the two parts as a unit, means for effecting axial movement of one of the parts independently of the other, and tables on said drums comprising a series of numbers representing the days of the month and each having a small number thereunder, another two part drum journalled in the casing, means for effecting rotation of the parts as a unit, means for effecting axial movement of one of the parts of the drum, tables on said parts comprising numbers representing the centuries by tens and units and having a small number under each and a third two part drum journalled in the casing, means for effecting rotation of the two parts as a unit, means for effecting axial movement of one of the parts independently of the other, and tables on said two parts containing numbers representing the years by tens and units and each having a small number thereunder.

5. A machine of the type described, comprising a casing having five windows therein, a drum journalled in the casing opposite one of the windows having a table thereon consisting of a column of numbers from 0 to 35 and a column of day names in chronological order and repeated with a day name opposite each number, another drum journalled in the casing opposite another window having a table thereon comprising a list of the months in chronological order and each having two small numbers thereunder, a two part drum journalled in the casing opposite another of the windows, means for rotating the two parts as a unit, means for effecting axial movement of one of the parts independently of the other and tables on said drums comprising a series of numbers representing the days of the month and each having a small number thereunder, another two part drum journalled in the casing, means for effecting rotation of the parts as a unit, means for efiecting axial movement of one of the parts of the drum, tables on said parts comprising numbers representing the centuries by tens and units and having a small number under each and a third two part drum journalled in the casing, means for effecting rotation of the two parts as a unit, means for effecting axial movement of one of the parts independently of the other, tables on said two parts containing numbers representing the years by tens and units and each having a small number thereunder, and means for indexing all of the drums.

6. In a machine for finding the day name of all dates from B. C. to 21,000 A. D. the combination comprising a casing having a plurality of windows on each side thereof, a movable day name indicator positioned to be displayed through one window on each side of the casing,

a plurality of movable indicators respectively positioned opposite the remaining windows, means exterior to the casing and connected thereto for moving each 'of the movable indicators independently of the other, two of said indicators having indicia thereon corresponding to the month date numbers, two of said indicators having indicia thereon corresponding to the month names, two of said indicators having indicia thereon corresponding to century numbers and two of said indicators having indicia thereon corresponding to the year numbers, and all of said movable indicators having indicator numbers thereon whereby the sum of the indicator numbers for any date displayed determines the position of the day name indicator to display the name of the day corresponding to that date.

7. In a machine of the type described for displaying the day name of any date from 45 B. C. to 21,000 A. D., comprising a casing having ten openings therein, movable indicators mounted in the casing, one common to two of said openings and one adjacent each of the others of said openings respectively, means for independently moving said indicators, charts on said indicators respectively comprising day names, day dates, month names, century numbers and year num bers, and indicator numbers on said charts whereby the sum of the indicator numbers displayed for any date determines the position of the day name indicator to display the day name of that date.

JOHAN KAREL ZEPPENFELDT LAMPE. 

